function Person(name, age, job) {
    this.name = name;
    this.age = age;
    this.job = job;
    this.friends = ['wcs', 'cj'];
}
Person.prototype = {
    constructor: Person,
    sayName: function () {
        console.log(this.name);
    }
}
let person1=new Person('wcs',27,'software')
let person2=new Person('wy',28,'it')
person1.friends.push('wy')
console.log(person1.friends);
console.log(person2.friends);
console.log(person1.friends===person2.friends);
console.log(person2.sayName===person2.sayName);